Cambered missile nose

ABSTRACT

To provide a more favorable undersea trajectory for missiles launched from a moving submarine the nose portion has a detachable cambered overlay axisymmetrically disposed at an angle of approximately 9* with respect to axis of the missile.

United States Patent Goedde et al. July 1, 1975 [5 CAMBERED MISSILE NOSE 3.091033 6/1963 Draim et al a. 89/].809 3.l35,204 6/1964 Menichelli et al... 102/54 [75] Inventors: Edmund F. Goedde, San Jose; Gary 3 196 823 7 1965 Th t H4 20 D. Hoover; Edward J. Barakauskas, ms on l l R both of Saratoga, all of Calif. [73] Assignee: Westinghouse Electric Corp., Primary Emmifler Benjamin Borchelt Pittsburgh, pa Assistant Exammer. T. Jordan Attorney, Agent, or FirmF. .l. Baehr, Jr. [22] Filed: Oct. 23, 1973 [Zl] Appl. No.: 408,959

[57] ABSTRACT [52] U.S. Cl. 4/20 R; 89/l.809 [5]] Int. Cl. F42b 15/20 To provide a more favorable undersea trajectory for [58} Field of Search 114/20 missiles launched from a moving submarine the nose 8 lO2/52-54 portion has a detachable cambered overlay axisymmetrically disposed at an angle of approximately 9 56} References Cited with respect to axis of the missile.

UNITED STATES PATENTS 2.338.322 1/1944 Ferret .4 H4/20 R 4 Claims, 3 Drawing Figures FLOW VELOCITY CAMBERED MISSILE NOSE BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to undersea launching of missiles or torpedoes from a submarine moving normal to the centerline of the missile or torpedo and more particularly to means for counteracting the hydrodynamic forces created by the crossflow.

2. Description of the Prior Art During the undersea launching of missiles from a moving submarine the relative velocity of the water with respect to the missile or crossflow, causes hydrodynamic forces, which produce moments that increase as the missile emerges from the launch tube causing the missile to contact the walls of the launch tube. As the length to diameter ratio of the missile becomes larger the moment increases, increasing the forces on the missile necessitating that the missile be made stronger to resist these forces.

To minimize the missiles pitch and translation during the launch, the launch tubes are lined with soft resilient adaptor pads which allow the missile to contact the walls of the launch tube during the launch, the contact area providing the resistance forces necessary to counteract the moments produced by the hydrodynamic forces acting upon the missile. Such a system has sev eral major drawbacks one of which is restraining the missile during the launch increases the hydrodynamic forces requiring that the missile be built to withstand these greater forces. Building a missile to withstand larger forces requires that the missile have a thicker skin, which in turn increases the weight of the missile and reduces its performance.

Providing launch tubes large enough to accommodate the missiles excursion results in excessively large diameter launch tubes, greatly reducing the number of launch tubes that can be carried by a submarine. Also, large diameter launch tubes do not provide sufficient restraining forces to guide the missile during the launch and result in the missile attaining undesirably large pitch angles which must be corrected, if the missile is to follow a reasonable trajectory and emerge from the water with an acceptable attitude.

SUMMARY OF THE INVENTION A missile for undersea launching from a moving submarine, when made in accordance with this invention, in general comprises a symmetrical nose cone portion forming the leading end thereof and a detachable cambered nose cone portion overlaying the symmetrical nose cone portion to reduce undesirable hydrodynamic forces and moments when said missile is being launched from a moving submarine.

BRIEF DESCRIPTION OF THE DRAWINGS The objects and advantages of this invention will become more apparent from reading the following detailed description in connection with the accompanying drawings, in which corresponding reference characters indicate corresponding portions throughout the drawings and in which:

FIG. 1 is a partial sectional view of a launch tube and a missile being launched;

FIG. 2 is a partial sectional view of a missile made in accordance with this invention emerging from a launch tube; and

FIG. 3 is a graph showing the underwater trajectory and pitch of cambered and straight nosed missiles under various launching conditions.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail and in particularly to FIGS. 1 and 2, there is shown a portion of an undersea vessel or submarine 1 having one or more launch tubes 3 from which a missile 4 or 41 is launched beneath the surface of the sea when the submarine is moving. The missiles 4 and 41 each have a central axis 5 and a symmetrical nose portion 6 which is axisymmetrically disposed about the central axis 5 and located at the upper or leading end of the missile 4 or 41.

In FIG. 1 the submarine l is assumed to be moving from left to right and the missile 4 is shown emerging from the launch tube 3. The movement of the submarine 1 from left to right produces a crossflow from right to left, indicated by the arrows 6. As the missile 4 emerges from the launch tube 3 the upward velocity of the missile and crossflow combine to produce hydrodynamic forces and moments causing the missile to pitch in a direction opposite to that in which the submarine is moving, which results in the missile contacting the launch tube walls 7. To prevent damage to the missile 4 and the launch tubes 3, the walls 7 are lined with an elastomer such as rubber, urethane, or other resilient material 8. The missile 4 contacts the lining 8 as it is launched producing a force which resists the hydrodynamic forces and moments created by the movement of the submarine and the missile during the launch. Since the missile 4 is restrained by the walls 7 of the launch tube 3, it must be built to withstand the stresses created by the hydrodynamic forces, which increase due to the restraints created by the walls 7 of the launch tube 3.

The missile 41, as shown in FIG. 2, is similar to the missile shown in FIG. 1 except that it has an axisymmetrical cambered nose portion 9 overlaying a portion of the symmetrical nose portion 6. The cambered portion 9 covers approximately 60 to of the symmetrical nose portion 6. The cambered nose portion 9 has an axis 11 disposed at an angle a with respect to the axis 5 of the missile. The angle a may vary between 5 and IS". The cambered nose portion 9 is shown to be parabolic and more blunt than the nose portion 6. However, it is understood that the cambered nose portion may take any shape however, as shown in FIG. 2, one embodiment shows a parabolic cambered nose portion 9 covering approximately 68% of the symmetrical nose portion 6 and having an angle a of approximately 9. The missile is oriented in the launch tubes 7 so that the axis 11 of the cambered portion 9 of the nose is disposed in a plane containing a vector representing the forward velocity of a forward moving submarine.

The cambered nose portion 9 is detachable and is provided with means for releasing it from the missile. Such means may include explosive cutting devices 10 which divide the cambered nose cone overlay 9 into a plurality of segments which would slide off the symmetrical nose portion 6 during the launch when the nose portion is adjacent the surface of the sea.

FIG. 3 shows the theoretical underwater trajectory of a group of missiles having a length of diameter ratio of 5.25 under different operating conditions.

Line 13 shows the trajectory and pitch of a missile with a symmetrical nose being launched with a crossflow velocity of 8.5 feet per second.

Line shows the trajectory and pitch of a missile 41 with a cambered nose disposed at an angle of 9 with respect to the axis of the missile and being launched with a crossflow velocity of 8.5 feet per second.

Line 17 shows the trajectory and pitch of a missile 4! with a cambered nose portion disposed at an angle of 9 with respect to the axis of the missile and being launched from a stationary position or having a zero crossflow velocity.

These curves represent theoretical values and recent tests on a l/30th scale model showed the theoretical values to be optimistic.

As seen in FIG. 3 overlaying the nose portion 6 of a missile 41 with an axisymmetrical nose portion 9 significantly afiects the trajectory of the missile and the pitch angle as it approaches the surface so that by selecting the proper cambered nose portion the pitch angle and trajectory of the missile may be optimized for launching the missile from a particular depth with a specific crossflow.

What is claimed is:

l. A missile for undersea launching from a moving submarine, said missile comprising a nose portion forming a leading end thereof, said nose portion having a symmetrical outer surface and an axisymmetric cambered nose portion overlaying said symmetrical nose portion, the axis of the cambered nose portion forms an angle of approximately 5 to approximately l5 with respect to the axis of the missile for reducing undesirable hydrodynamic forces and moments when said missile is being launched from said moving submarine.

2. A missile as set forth in claim 1, and further comprising means for detaching the cambered nose portion from the missile adjacent the surfaces of the sea.

3. A missile as set forth in claim I, wherein the missile and vessel are cooperatively associated so that the axis of the cambered nose portion and a vector indicating the forward velocity of the submarine are generally coplanar.

4. A missile as set forth in claim 1, wherein the cambered nose portion extends over 60 to of the symmetrical nose portion.

i i I. II: 

1. A missile for undersea launching from a moving submarine, said missile comprising a nose portion forming a leading end thereof, said nose portion having a symmetrical outer surface and an axisymmetric cambered nose portion overlaying said symmetrical nose portion, the axis of the cambered nose portion forms an angle of approximately 5* to approximately 15* with respect to the axis of the missile for reducing undesirable hydrodynamic forces and moments when said missile is being launched from said moving submarine.
 2. A missile as set forth in claim 1, and further comprising means for detaching the cambered nose portion from the missile adjacent the surfaces of the sea.
 3. A missile as set forth in claim 1, wherein the missile and vessel are cooperatively associated so that the axis of the cambered nose portion and a vector indicating the forward velocity of the submarine are generally coplanar.
 4. A missile as set forth in claim 1, wherein the cambered nose portion extends over 60 to 80% of the symmetrical nose portion. 